In telephony systems, such as the public switched telephone network (PSTN), a ringtone is an audible signal made by a callee device to indicate an incoming call. Typically, the callee device plays the ringtone after the callee device is alerted of an incoming call from a caller device, but before the incoming call is answered.
In recent years, personalized ringtones have become popular. This feature allows the user of a callee device to specify audio selections for various callers, so that the caller device plays a specific ringtone when the callee device receives an incoming call from a particular caller device. These audio selections can take any form, but are usually based on audio clips or files of content such as popular music, speeches, or sound effects.
Personalized ringtones can be used with both wireline communication devices, such as desktop phones, and wireless communication devices, such as cell phones. Regardless of the type of device, in these traditional systems, the ringtone is typically of low quality and is chosen by the user of the callee device and stored locally on the callee device.